1. Field of the Invention
The present invention relates to a roll mill, more specially for milling coal, with a gas-tight mill casing, a turning milling pan and a number of milling rolls, designed for rolling on the pan, each milling roll being joined with a rocker arm for turning about a rocker arm axis.
2. Description of the Prior Art
Such mills generally have a current of air or other gas, normally heated to be higher than the temperature of the outside air, moving through them. The air of the gas is used for drying the material to be milled and for transporting dust. The gas makes its way with a higher-than-atmospheric pressure, as produced by a separate blower, into the inlet or connection point of a gas space under the turning mill pan, which has a blade ring round it. Then the air or other gas makes its way through the blade ring round the pan into the milling or working space where it takes up milled material, drying it in suspension and then transporting the milled-up material to the classifier placed over the milling space.
Because many electricity works or power stations are being changed over at the present time from oil to coal, it has become necessary to make further modifications in the design of coal milling plants.